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Tropical Storm Eta Discussion Number  28
NWS National Hurricane Center Miami FL       AL292020
1000 AM EST Sat Nov 07 2020

Satellite imagery and surface data indicate that Eta has become a 
little better organized this morning, with the center re-forming to 
the northeast near an area of deep convection.  Surface 
observations from Grand Cayman Island show that the system has 
regained tropical-storm strength, and the initial intensity is 
increased to 35 kt.

The initial motion is uncertain dur to the reformation, with the 
best estimate of 055/15.  This general motion should continue for 
the next 24 h or so as Eta is steered by a mid- to upper-level 
trough over the Gulf of Mexico.  From 24-96 h, the trough is 
forecast to become a cut-off low, and Eta is expected to turn 
northward, northeastward, and eventually westward as it merges with 
the low.  There remains some spread in the guidance in just where 
these turns will occur and how close the center will come to south 
Florida and the Florida Keys.  This part of the new track is nudged 
just a little north of the previous track.  After 96 h, Eta should 
move slowly across the eastern Gulf of Mexico, with the forecast 
track showing a northward motion as a compromise of the 
poorly-agreeing guidance.

Although the storm is experiencing moderate to strong southwesterly 
shear, strong upper-level divergence caused by the trough should 
allow strengthening through about 48 h, although the cyclone may 
acquire some subtropical characteristics as it merges with the 
baroclinic system.  After that time, dry air entrainment is likely 
to cause Eta to slowly weaken through the remainder of the forecast 
period.  The new intensity forecast is unchanged from the old 
forecast.

The new forecast track requires a Tropical Storm Warning for south 
Florida and the Florida Keys at this time.

Key Messages:
 
1. Heavy rainfall will continue across the Cayman Islands, portions 
of Cuba and Jamaica, and will spread north into the Bahamas and 
southern Florida. This rain may result in significant, 
life-threatening flash flooding and river flooding in Cuba. Flash 
and urban flooding will also be possible for the Cayman Islands, 
Jamaica, the Bahamas and southern Florida.

2. Tropical storm conditions are expected today and Sunday in 
portions of the Cayman Islands, Cuba, and the northwestern Bahamas, 
where a Tropical Storm Warning is in effect.

3. Tropical storm conditions are expected by late Sunday in the 
Florida Keys and along portions of the southeast Florida coast, 
where a Tropical Storm Warning is in effect. Tropical storm 
conditions are possible elsewhere in portions of southern and 
central Florida beginning Sunday night, where a Tropical Storm Watch 
is in effect. Additional Tropical Storm Warnings will likely be 
needed later today.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  07/1500Z 19.6N  81.8W   35 KT  40 MPH
 12H  08/0000Z 20.8N  80.6W   40 KT  45 MPH
 24H  08/1200Z 22.5N  79.5W   45 KT  50 MPH...INLAND
 36H  09/0000Z 23.8N  79.3W   50 KT  60 MPH...OVER WATER
 48H  09/1200Z 25.0N  80.1W   55 KT  65 MPH
 60H  10/0000Z 25.8N  81.9W   55 KT  65 MPH
 72H  10/1200Z 26.2N  83.2W   50 KT  60 MPH
 96H  11/1200Z 26.5N  84.0W   45 KT  50 MPH
120H  12/1200Z 28.5N  84.0W   40 KT  45 MPH
 
$$
Forecaster Beven
 
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